A Sample Lesson on Solving a System of Equations with Two Unknowns

Before you begin, you may want to print the summary sheet below for reference. The sheet happens to have a major typo, but I think that it’s usually fun for the students to discover it themselves. I’ve been generous enough to correct the typo.

Start out by watching this introductory video about solving an application problem using the addition method. I recommend printing out the handout of what is covered in the video so that you can take notes as you follow along.

Go to Wolfram|Alpha and make sure that you know how to enter systems of equations there so that you can check your answer using this wonderful tool whenever you are at a computer. Or even on the go, if you have a smartphone.

This is a link to the solution for the problem shown in the video: http://www.wolframalpha.com/input/?i=solve+the+system+.34x+%2B+1.98y+%3D+3990%2C++.73x+%2B+2.45y+%3D+5865

Next, watch this short video on solving systems of equations using the substitution method.

If you have time, which I hope you do, please print out the page below, cut apart, and match the each system of equations with its correct solution.

Finally, here is a link to a wonderful on-line Jeopardy-style game for one or two players, that covers how to solve Systems of Two Equations (and Inequalities) with two unknowns.